BUR #36072 has been rejected.
create implication calyrex_(ice_rider) -> calyrex
create implication calyrex_(ice_rider) -> glastrier
create implication calyrex_(shadow_rider) -> calyrex
create implication calyrex_(shadow_rider) -> spectrier
These forms are just Calyrex riding Glastrier/Spectrier, so it would only make sense for their tags to imply both Pokémon.